In 1900, a worn bronze machine was hauled from an ancient Greek shipwreck. With dozens of crumbling gears, the machine puzzled experts for more than a century. This documentary follows researchers who have come to suspect the machine, known as the Antikythera mechanism, is a miniature planetarium that tracked the Sun and the Moon and could predict eclipses. They have created working models, down to the pin-and-slot mechanism that gives a slight wobble to the lunar orbit, and have used a custom X-ray machine to probe layers of corroded clockwork. The Greeks “managed to cram nearly all their knowledge of astronomy into this small-geared device,” the mathematician Tony Freeth says on-screen. The maker of this “analog computer” — perhaps a thousand years ahead of its time — is still unknown, but some believe it might have been inspired by the work of Archimedes.

THEATER

Extreme Whether. A play by Karen Malpede. Theater for the New City. 155 First Avenue. Readings April 8 at 7 p.m. (withJames Hansen) and April 13 at 8 p.m. $5.

A new “eco-drama” about climate change will have two readings this month. Set in upstate New York during the record-hot summers of 2004 and 2012, the play pits brother against sister in a bitter debate about the future of the planet. In one corner is John Bjornson, a composite of famous climatologists. In the other is his twin sister, Jeanne, an energy spokeswoman married to a skeptical lobbyist. “The play poses this most difficult question of whether we can act in our own defense” when faced with a global threat, says the playwright, Karen Malpede, a twin herself. After the reading on Monday, James Hansen, the NASA climate scientist who is retiring from the agency this week, will speak to the audience on how “we are nearly out of time, if we want to avoid creating a situation that will be out of control for today’s young people.”

It’s no secret that mathematicians and artists are drawn to simple and elegant works. But what is simplicity, exactly, and why do we like it? Scholars converging on the City University of New York this week will show that these questions aren’t as straightforward as they sound. The many speakers and panelists include the computer scientist Stephen Wolfram and the philosopher Jan Zwicky , who will argue it’s not simplicity so much as “potency of meaning” that gives the “sense we’ve seen into the heart of things.” Short films byRichard Serra, William Wegman andAndy Warhol will also screen, along with digital videos ofAndy Goldsworthy making “rain shadows” by lying on the ground during a storm.

Science trumps eye candy at this newly reopened gallery in Cambridge, Mass. Beyond the usual geodes and gemstones, the exhibit reveals how scientists have reconstructed the history of Earth and its life from data hidden in rocks. New samples include a two-billion-year-old chunk of iron from Michigan suggesting that ancient oceans held little oxygen, and a 250-million-year-old piece of Siberian basalt dating from the largest extinction in the planet’s history. At the opening lecture on Thursday, Francis A. Macdonald, the Harvard geologist who helped curate the new gallery, will explain how Arctic melting has allowed scientific exploration even as it has opened new sources of fuel, and will weigh the pros and cons of geological inquiry in delicate areas.